129826domain: NAppears in sequencesNumbers k such that k | 10^k + 9^k + 8^k + 7^k + 6^k + 5^k + 4^k + 3^k.at n=23A057283Numbers k such that 10^k + 4*R_k + 5 is prime, where R_k = 11...1 is the repunit (A002275) of length k.at n=20A102935